. Author manuscript; available in PMC: 2014 Aug 1.

Published in final edited form as: Hum Genet. 2013 Apr 17;132(8):10.1007/s00439-013-1304-5. doi: 10.1007/s00439-013-1304-5

Table 1.

Demographic information for Helsinki mothers genotyped on the Illumina exome beadchip. Numbers in the table are mean (standard deviation) except for dichotomous variables where percentages were used. P-values were determined using a one-way analysis of variance (ANOVA).

Variable	Preterm (n=237)	Term (n=328)	P-value
Maternal age (yr)	31.1 (5.0)	31.5 (4.2)	0.334
Body Mass Index (kg/m²)	23.5 (4.5)	22.7 (3.1)	0.012
Parity (n)	1.6 (0.89)	1.5 (0.73)	0.062
Gravidity (n)	2.1 (1.3)	1.9 (1.0)	0.050
Birth weight (g)	2337.0 (500.1)	3578.7 (421.3)	<0.0001
Birth length (cm)	45.0 (2.8)	50.3 (1.9)	<0.0001
Alcohol use (%)	5.2%	1.5%	0.012
Tobacco use (%)	8.7%	2.7%	0.002